By Katherine Kozlowski, Medical Writer and Contributor to Vein News and www.VeinsVeinsVeins.com
What is isolated calf vein thrombosis ?
Calf vein thrombi are defined by involvement of the axial veins (peroneal, posterior tibial, and/or anterior tibial veins) and/or muscular calf veins (soleal or gastrocnemius veins), not involving the popliteal or higher veins. Diagnosis must include imaging studies of the entire leg, including the calf.
Nicholson M and colleagues believe that that "conventional wisdom says that isolated distal DVT (calf vein thrombosis) rarely causes symptomatic pulmonary embolism"
Kuckzmik W et al from the Mayo Clinic in Minnesota have given us some guidelines regarding the muscular calf vein versus axial calf vein thrombosis.
What was the study method?
Consecutive patients with ultrasound confirmed acute DVT involving the calf veins (January 1, 2016-August 1, 2018) were identified from the Gonda Vascular Center ultrasound database. Patients were divided into axial or muscular groups based on thrombus location. Demographics, management, and outcomes were compared.
What are the results of this study?
1. Over the study period, there were 647 patients with calf DVT equally distributed between axial (n = 321) and muscular (n = 326) locations. Within these groups, peroneal and soleal veins were most commonly involved.
2. Nearly all cases were provoked (97%).
3. Synchronous pulmonary embolism (PE) were more common for axial (30.8%) compared to muscular groups (20.2%; p = 0.001); nearly one-third had no pulmonary symptoms.
4. Anticoagulation for a median of 3 months was initiated for 85.5% of both groups.
5. Venous thromboembolism (VTE) recurrence was more common in the axial group (15.9% vs. 7.1%, p = 0.0015) including more frequent DVT propagation (9.4% vs. 3.1%; p = 0.0017) and PE (3.4% vs. 0.6%; p = 0.0168).
6. Withholding anticoagulation led to more frequent thrombus propagation in the axial group (3.4% vs. 0.9%; p = 0.029).
What are the conclusions of this study?
Axial DVT are more likely to have an associated PE and are more likely to experience recurrent VTE, particularly if anticoagulation is withheld.
Nicholson M, Chan N, Bhagirath V, Ginsberg J. Prevention of venous thromboembolism in 2020 and beyond. Journal Clin Medicine 2020; 9(8): 2467.
Kuczmik W, Wyzokinski WE, Hesley GK, Vlazny DT, Houghton DE, Swabson KE, Casanegra AI, Hodge D, White L, McBane 2nd RD.
Calf vein thrombosis comparison of outcomes for axial and muscular venous thrombosis. Thromb Haemost 221; 121(2): 216-223.